Smart Pyrolysis: Chemical Recycling for PU Rigid Foam on laboratory scale
The challenge: End-of-life reality for rigid foam insulation
Europe's MDI market for rigid foam is expanding rapidly – driven by rising demand for more efficient insulation materials in the construction sector and by appliance applications such as refrigerators. Yet recycling crosslinked rigid foams from construction and appliances remains challenging due to their chemical composition. Mechanical recycling reaches its limits, making chemical recycling essential to break molecular bonds and recover valuable raw materials.
The breakthrough: Smart pyrolysis delivers virgin-quality materials
Working alongside Fraunhofer UMSICHT, we've developed smart pyrolysis – an innovative chemical recycling technology that transforms what both industries considered impossible into reality. This advanced thermal process converts rigid PU foam waste from buildings and appliances into high-purity re-aniline at approximately 99% purity.
This breakthrough enables the production of recycled MDI with virgin-like quality and a significantly lower carbon footprint. We at Covestro source the chemically recycled feedstock generated through this technology and incorporated it into our production processes. replacing fossil-based raw materials and advancing circular MDI solutions All while maintaining the performance standards the industries demand.
Smart pyrolysis represents a paradigm shift for our industry. We're not just recycling foam waste, we're fundamentally reimagining how construction and appliance materials can become truly circular.
The impact: Up to 80% lower CO₂ emissions
Life cycle assessment results demonstrate the transformative potential: re-aniline production via smart pyrolysis achieves up to 80% lower CO₂ emissions compared to fossil-based aniline production. This translates into around 40% lower emissions for pMDI and a 25–30% reduction in PIR foam – substantial contributions to reducing the carbon footprint of materials in the construction and appliance industries.
Chemical recycling vs. mechanical recycling of PU rigid foam
To fully enable circular material flows in construction and appliances, it is essential to understand how chemical recycling differs from mechanical approaches. While mechanical recycling can process clean and homogeneous waste streams, it may result in downcycled materials with reduced performance and limited application potential—especially when dealing with mixed construction and demolition waste.
Chemical recycling offers a complementary approach. By breaking molecular bonds, smart pyrolysis enables true foam waste recycling at the chemical level. This allows valuable raw materials such as re-aniline to be recovered in high purity, independent of the original product form or application. As a result, chemical recycling of rigid foam helps enable a circular economy and long-term material circularity.
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Project partners from Covestro und Fraunhofer UMSICHT advancing chemical recycling. -
Components of the smart pyrolysis recycling process.
From lab to reality: Pilot plant development
Smart pyrolysis has proven its effectiveness from laboratory bench to mini-plant scale across both construction and appliance waste streams.
The next milestone: a pilot plant at Fraunhofer UMSICHT with 2,000 tons annual capacity, operational by 2028. This facility will demonstrate industrial-scale viability using optimized catalysts and process conditions.
Smart pyrolysis is the result of years of joint research. With the pilot plant, we are moving from technical feasibility to industrial implementation, optimizing the process at scale and preparing recycled raw materials for market use.
Key benefits
- Circular: Transforms waste from buildings and appliances into virgin-quality raw materials.
- Low-carbon: Achieves up to 80% lower CO₂ emissions compared to fossil alternatives.
- Scalable: Pilot plant development paves the way for commercial implementation.
- High-purity: Produces ~99% pure re-aniline suitable for premium applications.
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